Olmec lodestone bar (possible compass)
Barra magnética olmeca (posible brújula)
- Date
- c. 1000 BCE · confidence low
- Place
- San Lorenzo Tenochtitlán, Texistepec, Veracruz, Mexico
- Credited to
- Olmec culture
- Field
- Movement
⚠️ Disputed: the sources disagree.
What was discovered
A polished fragment of haematite with a groove that, when floated, orients itself stably. If it was used this way, it would be the oldest known use of magnetism.
The M-160 piece (found in 1967) and its interpretation as a compass (Carlson, 1975) are unconfirmed; its context is poorly documented. In any case, it predates the Chinese 'Si Nan' compass.
What it led to
- the orientation of Olmec buildings
- debate over pre-Columbian knowledge of magnetism